The present invention generally relates to non-volatile memory devices, and more particularly to methods and systems extending the shelf life of non-volatile memory devices.
In general, non-volatile memory is used for secondary storage or long-term persistent storage. One widely used form of primary storage today is a volatile form of random access memory (RAM), meaning that when the computer is shut down, anything contained in RAM is lost. Non-volatile memory technologies can be attached to computer systems as storage, such as DRAM, and can be used for long term storage that is not attached to a computer system, such as magnetic tape.
Currently for storage where a device is not accessed for long periods, sometimes years (termed “very cold storage”), tape is an attractive often used technology because it has a very long retention time. In contrast, data retention time for solid state non-volatile memory devices is limited and must be considered not only during runtime, but when these are on shelves in distribution warehouses or customer locations. Currently, when a non-volatile memory device is powered off there is no existing methodology to refresh their data in order to extend the shelf life of the non-volatile memory device.
In one example, a flash drive may have a data retention life of three months, meaning that beyond the time period of three months, there is a risk of losing the data as well as unpredictable firmware behavior the next time it is powered on.